Sound-record cinematograph film



Patented 13, 1932 UNITED STATES PATENT ornca THOMAS THOBNE BAKER, OI HATCH END, MIDDLE-EX, ENGLAND, ASSIGNOB '1'0 SPICERS LIMITED, 01' LONDON, ENGLAND, A BRITISH COMPANY CINEIATOGBAIPH III! 80 Drawing. Application fled June 20, 1980, Serial No. 482,895, and in Great Britain July 1, 1988;

This invention comprises improvements in g; relating to sound-record cinematograph It is well known that, in the so-called talking films, the sounds are reproduced by means of a photographic record printed on a narrow strip about one-tenth of an inch in width at one side of the picture record. This invention relates to improvements whereby such 10 a strip would-in a colour film-be substantially an ordinary black and white photographic film devoid of any colour and allowing) of the sound-record to be photographed in lack and white.

Where the colours of the film de end upon a matrix or multicolor screen of primary colours over which the emulsion is coated, it

is necessary to have an uncoloured transparent strip at one side of the cinematograph film on which the sound-record is to be printed, for any pattern in-a multicolor screen or matrix on the sound track (i. e. the portion of the film upon which the sound-record is printed) would give rise to high frequency interruptions which would produce obj ectionable parasitic sounds or ground noise.

According to this invention in the manufacture of sound-record cinematograph films in natural colours, prior to the ap lication of 80 the multicolor screen to the sur ace of the film, there is applied to that portion of the film which is to serve as the sound track, a

layer of material to protectithe underlying portlon of the film from the dyes used in '85 making the multicolor screen;

In a referred form of the invention the materia employed to protect the sound track comprises a varnish such, for example, as bitumen dissolved in benzole.

- 40 A ractical example of the method of carryin t e invention into effect will now be given. The film base, which comprises a cel ulose acetate film, is coated along that portion kn which is to serve as the sound-track with a a 46 strip of a bitumen-containing varnish of the the surface of the film base which is protected by the strip of varnish. The varnish comprises a solution of bitumen in benzole,

and it is applied to the film by means of a small felt roller which is kept moist with the varnish by means of a feeding roller.

A layer of collodion containing a green dye, the porosity of which layer has been 1ncreased by the addition thereto of 1 part in 4000 of water, is then applied to the whole surface of the film. The multicolor screen is then formed on the surface of the collodion layer by ruling on lines of a fatty resist, bleachin the green dye from the spaces unprotected by the resist, re-dyein the bleached spaces in another colour and ally removing the resists in the manner described in U. S. Patent 1,805,361.

When the surface of the collodion layer is treated with benzole to remove the resists, it will be found that the collodion is sufiiciently porous to allow the benzole to penetrate through it and to dissolve the underlying bitumen. The strip of bitumen varnish, together with that portion of the collodion layer which overlies it, then comes away from the film base, thus leaving bare a clear strip alongrthe film base which serves as the sound trac If desired, in order to obtain a three color screen, a further strip of bitumen-containing varnish may be applied to the sound track, and a second series of lines of fatty resists can then be ruled on the film at an angle to the first series, and the bleaching, re-dyeing agd resist-removing operation can be repeate In the subsequent coating with sensitive emulsion there will thus be a strip of emulsion one-tenth of an inch in width with no multicolor screen beneath it upon which the sound-record can be printed in the wellown manner.

I claim I 1. A method of making a sensitive film of the multicolor screen type for use in the production of sound record cinematograph films in natural colours which comprises. applying to a cellulose acetate film, along a narrow strip which is to serve as a sound record track, a layer of bitumen dissolved in benzole,-coatin the surface of the film with a layer of co odion forming a multicolour screen onthe collodion layer, treating the film with benzole to remove the bitumen together with that portion of the collodion layer which overlies the said layer of bitumen and finally coating the film thus prepared with a photographic emulsion.

2. A method of making a sensitive film of the-multicolour screen type for use in the roduction of sound record cinematograph Elms in natural colours which comprises applying to a cellulose acetate film, along a narrow stri which is to serve as a sound rec-- ord trac ,a layer of bitumen dissolved in benzole, coating the surface of the film with a layer of collodion containing a small proportion of water, forming a multicolour screen on the collodion layer, treating the film with benzole to remove the bitumen to gether with that portion of the collodion layer which overlies the said layer of bitumen and finally coating the film thus prepared with a photographic emulsion.

3. A method of making a sensitive film of the multicolour screen type for use in the roduction of sound record cinematograph ms in natural colours which comprises applying to a cellulose acetate film strip which is to serve as a sound record track, a layer of bitumen dissolvedin benzole, coating the surface of the film .with a layer of dyed collodion containing a small proportion of water, applying a series of lines of greasy ink to the collodion surface,.bleaching the dye from the spaces unprotected by the lines of gre spaces in anot er colour, removing the lines of greasy ink, treating the film with benzole A to remove the bitumen together with that portion of the collodion layer which overlies the said layer of bitumen and finally coating the thus prepared with aphotographic emulsion.

4. A method of making a sensitive film of the multicolour screen t pc for use in the roduction of sound record cinematograph films in colours which comprises applying to a cmematograph film along a narrow strip 7 which is to serve as a sound record track a layer of a resist material capable of protecting the underlying portion of the film from the action of dyes, eoatin the surface of the foo solvent for the resist with a layer of co odion porous to a material, forming a mult colour screen on said collodion .layer, treating the fi1'm with a solvent to remove the mat material, removing that portion of the collodion la er which overlay the resist material, and y coatin the film thus prepared wlth a hotograp ic emulsion.-

- 6. A meth of making a sensitive film of the multicolour screen type for use in the production of sound record cinematograph along a narrow ink, re-dying the bleached films in natural colours which comprises applying to a cinematograph film along a narrow strip which is to serve as a sound record track a protecting layer of bitumen dissolved in benzole, coating the surface of the film with a layer of collodion porous to benzole, forming a multicolour screen on said collodion layer, treating the film with benzole to remove the bitumen together with that portion of the collodion lying thereover, and

coating the film with a photographic emulsion.

6. A method of making a sensitive, film of the multicolour screen type for use in the roduction of sound record cinematograph s in natural colours which comprises applying to a cinematograph film alon a narrow strip which is to serve as a soun record track a layer of a resist material capable of protecting the underlying portion of the film from the action of dyes, coating the surface of the film with a layer of collodion containing a small proportion of water, forming a multicolour screen on said collodion layer,

treating the film with a solvent to remove the resist material, removing that portion of the collodion la er which overlay the resist material, and fihally coating the film thus prepared with a photographic emulsion.

In testimony whereof I afiix m signature.

THOMAS THORNE AKER. 

